|  | Haskell Thrift Bindings | 
|  |  | 
|  | License | 
|  | ======= | 
|  |  | 
|  | Licensed to the Apache Software Foundation (ASF) under one | 
|  | or more contributor license agreements. See the NOTICE file | 
|  | distributed with this work for additional information | 
|  | regarding copyright ownership. The ASF licenses this file | 
|  | to you under the Apache License, Version 2.0 (the | 
|  | "License"); you may not use this file except in compliance | 
|  | with the License. You may obtain a copy of the License at | 
|  |  | 
|  | http://www.apache.org/licenses/LICENSE-2.0 | 
|  |  | 
|  | Unless required by applicable law or agreed to in writing, | 
|  | software distributed under the License is distributed on an | 
|  | "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY | 
|  | KIND, either express or implied. See the License for the | 
|  | specific language governing permissions and limitations | 
|  | under the License. | 
|  |  | 
|  | Compile | 
|  | ======= | 
|  |  | 
|  | Use Cabal to compile and install; ./configure uses Cabal underneath, and that | 
|  | path is not yet well tested. Thrift's library and generated code should compile | 
|  | with pretty much any GHC extensions or warnings you enable (or disable). | 
|  | Please report this not being the case as a bug on | 
|  | https://issues.apache.org/jira/secure/CreateIssue!default.jspa | 
|  |  | 
|  | Chances you'll need to muck a bit with Cabal flags to install Thrift: | 
|  |  | 
|  | CABAL_CONFIGURE_FLAGS="--user" ./configure | 
|  |  | 
|  | Base Types | 
|  | ========== | 
|  |  | 
|  | The mapping from Thrift types to Haskell's is: | 
|  |  | 
|  | * double -> Double | 
|  | * byte -> Data.Word.Word8 | 
|  | * i16 -> Data.Int.Int16 | 
|  | * i32 -> Data.Int.Int32 | 
|  | * i64 -> Data.Int.Int64 | 
|  | * string -> Text | 
|  | * binary -> Data.ByteString.Lazy | 
|  | * bool -> Boolean | 
|  |  | 
|  | Enums | 
|  | ===== | 
|  |  | 
|  | Become Haskell 'data' types. Use fromEnum to get out the int value. | 
|  |  | 
|  | Lists | 
|  | ===== | 
|  |  | 
|  | Become Data.Vector.Vector from the vector package. | 
|  |  | 
|  | Maps and Sets | 
|  | ============= | 
|  |  | 
|  | Become Data.HashMap.Strict.Map and Data.HashSet.Set from the | 
|  | unordered-containers package. | 
|  |  | 
|  | Structs | 
|  | ======= | 
|  |  | 
|  | Become records. Field labels are ugly, of the form f_STRUCTNAME_FIELDNAME. All | 
|  | fields are Maybe types. | 
|  |  | 
|  | Exceptions | 
|  | ========== | 
|  |  | 
|  | Identical to structs. Use them with throw and catch from Control.Exception. | 
|  |  | 
|  | Client | 
|  | ====== | 
|  |  | 
|  | Just a bunch of functions. You may have to import a bunch of client files to | 
|  | deal with inheritance. | 
|  |  | 
|  | Interface | 
|  | ========= | 
|  |  | 
|  | You should only have to import the last one in the chain of inheritors. To make | 
|  | an interface, declare a label: | 
|  |  | 
|  | data MyIface = MyIface | 
|  |  | 
|  | and then declare it an instance of each iface class, starting with the superest | 
|  | class and proceding down (all the while defining the methods).  Then pass your | 
|  | label to process as the handler. | 
|  |  | 
|  | Processor | 
|  | ========= | 
|  |  | 
|  | Just a function that takes a handler label, protocols. It calls the | 
|  | superclasses process if there is a superclass. |